where \(S_{sample}\)  (\(S_{bg}\) ) is the area of a peak in
the sample (background) spectrum; \(t_{sample}\)  (\(t_{bg}\) ) is the
time of the sample (background) measurement; \(\epsilon \)  is the
\(\gamma \) -ray emission intensity of the corresponding transition;
\(\eta \)  is the full energy peak efficiency; \(m\)  is the sample mass.
The detection efficiencies were calculated with the EGSnrc
simulation package [1]}, [2]}, the events
were generated homogeneously in the Pt sample. The Monte Carlo
models of the two detectors have being validated through several
participations in proficiency tests and an additional validation
measurement was done using a \(^{57}\) Co point \(\gamma \)  source. The
standard deviation of the relative difference between the
simulations and the experimental data is \(3.3\%\)  for \(\gamma \) -ray
peaks with energies 122.1 keV and 136.5 keV for the detectors Ge7
and Ge15. The estimated specific activities of radioactive
impurities in the platinum are presented in Table
REF .
<TABLE>